1. Field of the Invention
This invention relates to a composition of the plant Withania somnifera, and, more particularly to a high purity extract composition with advantageous levels of withanolides glycosides, sitoindosides and oligosaccharides, and substantially low levels of free withaferin A, which provides enhanced cognition-enhancing effects for the user, and an extraction process for obtaining such composition, as well as pharmaceutical and nutritional use products thereof.
2. Description of the Prior Art
The plant Withania somnifera Dunn. (Solanaceae), commonly known as Ashwagandha, has been used in herbal formulations of the Ayurvedic or Indian system of medicine to attenuate a cerebral function deficit in the geriatric population, and to augment the faculty of learning and memory to provide a non-specific host defense. These beneficial effects help the organism to ward off stress and act as an adaptogen. Ashwagandha also shows significant protection against pentylene tetrazole-induced seizures in experimental models of epilepsy, indicating its potential utility for treatment of petitmal epilepsy. Ashwagandha administration also produces a decrease in the core body temperature suggesting a reduced Body Merabolic Rate (BMR), enhanced body growth and increased longevity.
Typically, commercially available extracts of Ashwagandha obtained from old roots stock are either completely devoid of sitoindosides, or contain only traces of sitoindosides admixed with large amounts of toxic metabolites of withanolide aglycones, and polysaccharides, and wherein the polyoxygenated withasteroids are degraded during conventional extract prodecures. Moreover, admixture of several undetermined chemo-types of such wild-crafted Withania roots create further complications in respect of their chemical ingredients. For example, the Solanaceae alkaloids, i.e. the Withania family of the tropane-type, e.g. scopolamine, encountered in such Withania plant species, when present in the extract, causes adverse effects, particularly, amnesia, instead of the beneficent cognition-enhancing effect for which Ashwagandha is renowned. Cultivated withania roots also are devoid of any alkaloid (the Dragendorff-responsive spots is due to interaction with withanolide aglycones). Furthermore, high levels of polysaccharides are present in such commercially available Withania somnifera extracts which adversely affect the bioavailability of the active compounds present therein.
Accordingly, it is an object of this invention to provide a new and improved extract powder composition from selected Withania somnifera plants which contain advantageous proportions of those components which provide an optimum biological effect for the user.
Another object herein is to provide such an extract composition having defined amounts of withaferin glycosidic conjugates and oligosaccharides but with only little free cytotoxic withaferin A therein.
Yet another object of the invention is to provide a process for obtaining such Withania somnifera plant compositions by extracting selected Withania somnifera plant material immediately after harvesting, thereby to prevent hydrolysis of the withanolide glycosides/sitoindocides therein.
Still another object of the invention is to provide pharmaceutical and nutritional use products which include the extract composition of the invention.
A feature of the invention is the provision of a Withania somnifera plant extract composition having substantial amounts of sitoindosides and other withanolide glycosides, low molecular weight oligosaccharides, and particularly characterized by very low levels of cytotoxic withasteroid aglycones.
Another feature herein is to provide such an extract composition without inducing hybridization by cross-pollination which would reduce the number and content of withanolide glyosides and sitoindosides, and augment any biologically inactive high molecular weight polysaccharides.
These and other objects and features of the invention will be made apparent from the following more detailed description thereof.